Regulation of the intestinal epithelial response to cyclic strain by extracellular matrix proteins.

SPECIFIC AIMComplex patterns of mechanical deformation may stimulate intestinal epithelial proliferation. Since the matrix modulates static intestinal epithelial biology, we examined whether matrix proteins could influence the intestinal epithelial response to cyclic strain in vitro (using human Caco-2 and nontransformed human intestinal primary epithelial cells, HIPEC, as models); finding that fibronectin inhibited the effects of cyclic strain, we sought the mechanism of this effect.PRINCIPAL FINDINGS1. Cyclic strain on basement membrane collagen I and collagen IV stimulates proliferation and activates FAK and MAPK similarly, but strain yields different results on fibronectin or laminin substrates10% strain at 10 cycles/min was similarly mitogenic on collagen I and collagen IV. Stimulation of proliferation on laminin was less, but significant. However, strain inhibited proliferation on fibronectin-coated membranes. Strain stimulated phosphorylation of focal adhesion kinase (FAK), ERK 1, and ERK 2 in cell...